Segmented windings are commonly used in modern electrical machine applications, such as alternators or hybrid-electric vehicles. These windings typically comprise a plurality of segmented conductors that are inserted into slots of the stator and connected at their ends to form phase windings on the stator. Most of the segmented conductors are connected to immediately adjacent conductors. However, jumpers or other connection members are used to provide connections between conductors that are separated from one another on the stator core. These jumpers must be strategically located on the stator in order to reduce crowding between the conductors and jumpers near the end of the stator. If the conductors and jumpers are not strategically positioned, it may be difficult to properly connect the phase windings to a rectifier bridge. Additionally, increased crowding at the end of the stator may introduce increased risk for electrical shorting between the segmented conductors, jumpers and/or terminals.
The segmented conductors may be provided in various forms, but often have a rectangular cross section. Additionally, the segmented conductors are often provided as U-shaped conductors which include two legs and a central U-turn portion between the legs. Thus, the segmented conductors are sometimes referred to as “U-shaped conductors” since their shape can resemble a U. However, the terms “conductor segment” and “segmented conductor” as used herein are not intended to be limited to U-shaped conductors, and instead refers generally to a distinct conductor segment having two ends, whether or not a U-shaped portion is included between the two ends.
Each segmented conductor is positioned in the slots of the stator such that the ends of the legs extend from one end of the stator (i.e., the “connection end” or “weld end” of the stator) and the U-turn portion extends from the opposite end of the stator (i.e., the “insertion side” of the stator). The leg ends are bent and then connected together on the connection end of the stator to form phase windings. The connections between the conductors include connection of adjacent leg ends that are welded together and connections between non-adjacent leg ends that are connected through jumpers.
In a typical segmented winding arrangement, the connection end of the stator tends to be crowded. First, the leg ends, which are already very closely aligned at the connection side, are made even more crowded by the welding points between adjacent leg ends. In addition, the jumpers between windings sets, phase path connections, neutral connections, and terminal connections cause additional jam in the crowded segmented welding points. This makes assembly of the electric machine difficult and increases the risk for potential short circuits and other defects during production.
In addition to crowding at the connection end of the stator, the existence of jumpers and terminals typically requires elongation of the clearance machine at the connection end of the stator. In many applications, such as electric vehicle applications, the compartment holding the electric machine is already crowded and it is difficult to find additional space for the increased clearance of the electric machine at the connection end.
Accordingly, it would be advantageous if a winding arrangement could be provided where the overall clearance required for the electric machine in an application compartment is decreased. It would also be desirable to provide a segmented winding arrangement where the crowding at the connection end of the stator is reduced. It would be of further advantage if such winding arrangement could be provided such that the electric machine may be easily manufactured, thus reducing manufacturing costs. It would also be advantageous if the winding arrangement resulted in decreased incidence of manufacturing errors. While it would be desirable to provide an electric machine that provides one or more of these or other advantageous features as may be apparent to those reviewing this disclosure, the teachings disclosed herein extend to those embodiments which fall within the scope of the appended claims, regardless of whether they accomplish one or more of the above-mentioned advantages.